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    <title>Document</title>
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    <script>
        let arr =[1,2,3,4,5,6,6,6,6];
        let arr2 = [3,4,5,6,7,8,9];

        // 并集 将2个数组的值合并起来。 - 去重
        let arr3 = [...new Set([...arr,...arr2])];

        console.log(arr3); //[1, 2, 3, 4, 5, 6, 7, 8, 9]

    </script>
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